In the construction of buildings having pitched roofs, truss members are secured to the underlying support structure of the building through the use of a truss anchorage device. Existing truss anchorage devices are fabricated as a unitary band of material, usually a semi-pliable metal, with bends at various locations to form a cap portion, two opposed wing portions, and two opposed attachment flanges.
The cap portion is located in the approximate middle of the unitary band and extends over the distal end of the top chord of the truss member. The two opposed wing portions extend horizontally downwardly from the cap portion at ninety degree (90.degree.) angles to the cap portion on opposite sides of the truss member and are bent vertically at a ninety degree (90.degree.) angle relative to the planar surface of the cap to extend at a spaced apart interval within the same plane and adjacent to the surface of an exterior edge of an underlying horizontally extending wall support frame member, thereby functioning as a retaining surface relative to positioning of the truss in relation to the exterior surface of the wall support frame. Extending downwardly from each wing portion is an attachment flange, bent at a ninety degree (90.degree.) angle relative to the planar surface of the wing portion, to allow attachment of the truss anchorage to opposed surfaces of the underlying vertically extending support stud. Thus, the unitary band of material in existing truss anchorage devices is subjected to at least six areas of deformation to create the ninety degree (90.degree.) angles to form the cap portion, the two wing portions, and the two attachment flanges, thus creating six potential areas of weakness or possible failure of the truss anchorage device.
In other existing truss anchorage devices, two separate unitary band of material are used, deleting the cap portion, and thereby deleting two of the ninety degree angles (90.degree.) of deformation in the device. Although deletion of the cap portion reduces the number of deformations in the band of material forming the anchorage device, it also reduces the degree of stability realized through use of a single unitary band of material including the cap portion extending over the distal end of the top chord of the truss member.
In addition to weakness created by the multiple bends or deformations in the surface of the unitary bands of material, the same number of fasteners, such as nails or screws, must be used in each of the opposed attachment flanges for anchoring the truss anchorage device to the opposed sides of the underlying support stud. Thus, the total number of fasteners used is split in half for the two opposed attachment locations, thereby limiting the strength at any one attachment location to half of the total strength provided by the fasteners should they be placed in a single location.